Tens of millions of Americans woke up this morning to discover not only a changed government, but a 4G network that sprouted up over night. No, there was no wizardry from any carrier to pull off such an impossible feat; T-Mobile just did what many writers have been telling it to do for months: call HSPA+ a 4G network.

Last night, T-Mobile laid claim to “America’s largest 4G network” when it launched a campaign that officially refers to HSPA+ as 4G technology. For several months, T-Mobile has avoided calling its 3G network upgrade 4G, but often noted that it delivers 4G speeds. Big Magenta is now going full force with 4G lingo and sending shots at competition in a television advertisement that just began airing.

This doesn’t sit well with Sprint, the self-named first 4G network. Sprint 4G President Matt Carter issued a statement to FierceWireless that

“Halloween is over – it’s time for T-Mobile to stop dressing up like their favorite super hero – Sprint 4G.”

This cat fight in the making stems from the decision by the International Telecommunications Union that neither WiMax nor LTE are true 4G technology. Despite that opinion, Sprint – and soon AT&T and Verizon – have decided to forge ahead by putting the “4G” label on their next round of network upgrades. T-Mobile has been on the sideline with its HSPA+ network, that offers speeds that equal or surpass that of Sprint’s WiMax, so it was only a matter of time before the carrier wised up and declared its network to be 4G.

We’ve already covered why T-Mobile’s former 3G network is faster than Sprint’s 4G network, so my stance on this issue is clear: if T-Mobile has a network that’s faster, larger, and more reliable than Sprint, they’d be fools not to brand it on equal footing as the competition. Now we put it in the hands of consumers to decide which 4G network is better for them.

T-Mobile today announced added 4G support for Chicago; Colorado Springs, Colo; Ft. Wayne, Ind.; Louisville, Ky.; and Raleigh-Durham and Wilmington, N.C. That brings the total number of metro areas with T-Mobile 4G to 75. T-Mobile plans to cover 200 million people, which is about 64 percent of the current U.S. population estimate (310,625,000), by the end of the year.